Method, apparatus and computer program for power control related to random access procedures

US 20090286566A1
Filed: 05/05/2009
Published: 11/19/2009
Est. Priority Date: 05/05/2008
Status: Active Grant

First Claim

Patent Images

1. A method comprising:

using a processor to initialize for i=0 a first power control adjustment state g(i) for an uplink control channel and a second power control adjustment state f(i) for an uplink shared channel to each reflect an open loop power control error;

using the processor to compute an initial transmit power for the uplink shared channel using full pathloss compensation, wherein the initial transmit power depends on a preamble power of a first message sent on an access channel, and is initialized with the second power control adjustment state f(0); and

sending from a transmitter a third message on the uplink shared channel at the initial transmit power.

View all claims

4 Assignments

Timeline View

Assignment View

0 Petitions

Accused Products

Abstract

A first power control adjustment state g(i) and a second power control adjustment state f(i) are initialized for i=0 to each reflect an open loop power control error. An initial transmit power for a shared uplink channel is computed using full pathloss compensation. The computed initial transmit power depends on a preamble power of a first message sent on an access channel, and the initial transmit power is initialized with the second power control adjustment state f(0). A third message is sent from a transmitter on an uplink shared channel at the initial transmit power. In various implementations, the power for i=0 on the uplink control channel is also initialized similar to the initial transmit power for the third message and using full pathloss compensation, and after the third message (and retransmissions of it), subsequent messages sent on the uplink shared channel are sent at a power that is computed using fractional pathloss compensation.

80 Citations

View as Search Results

20 Claims

1. A method comprising:
- using a processor to initialize for i=0 a first power control adjustment state g(i) for an uplink control channel and a second power control adjustment state f(i) for an uplink shared channel to each reflect an open loop power control error;
  
  using the processor to compute an initial transmit power for the uplink shared channel using full pathloss compensation, wherein the initial transmit power depends on a preamble power of a first message sent on an access channel, and is initialized with the second power control adjustment state f(0); and
  
  sending from a transmitter a third message on the uplink shared channel at the initial transmit power.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- - 2. The method according to claim 1, wherein the first message comprises a random access request message, the method further comprising:
    - computing the preamble power using full pathloss compensation,sending from the transmitter on the access channel the first message and in response receiving at a receiver a second message that comprises an allocation of resources on which the third message is sent;
      
      and after sending the third message, the method further comprises using the processor to compute an updated transmit power for the uplink shared channel using fractional power control and sending from the transmitter a subsequent message on the uplink shared channel using the updated transmit power.
  - 3. The method according to claim 1, wherein the second power control adjustment state f(i) for i=0 is initialized as:
    - P₀_—_UE_—_PUSCHf(0)=Δ
      
      P_PC+Δ
      
      P_rampup;
      
      wherein;
      
      P₀_—_UE_—_PUSCHis a power control constant for the uplink shared channel that is specific for a user equipment executing the method;
      
      Δ
      
      P_rampupis a ramp-up power for preamble transmissions; and
      
      Δ
      
      P_PCis a power control command indicated in a second message that is received in response to sending the first message.
  - 4. The method according to claim 1, wherein the first power control adjustment state g(i) for i=0 is initialized as:
    - P₀_—_UE_—_PUCCH+g(0)=Δ
      
      P_PC+Δ
      
      P_rampup;
      
      wherein;
      
      P_O_—_UE_—_PUCCHis a power control constant for the uplink control channel power that is specific for a user equipment executing the method.
  - 5. The method according to claim 4, wherein P₀_—
    - _UE_—_PUSCH=P_O_—
      
      UE_—_PUCCH=0 when computing initial values at i=0 of power control states for the respective shared and control channels.
  - 6. The method according to claim 1,wherein the initial transmit power P_Msg3of the third message for i=0 is equal to:
    - P_Msg3=min{P_max,P_preamble+Δ
      
      _0,preamble_—_Msg3+10 log₁₀(M_PUSCH(i))+Δ
      
      _TF(TF(i))};
      
      in which;
      
      P_MAXis a maximum allowed transmission power;
      
      P_preambleis the preamble power of the first message;
      
      M_PUSCH(i) is determined from an uplink resource allocation of a second message received in response to sending the first message;
      
      Δ
      
      _TF(TF(i)) is calculated from received signaling;
      
      Δ
      
      _PC_—_Msg3is indicated by a power control command received at the receiver; and
      
      Δ
      
      _0,preamble_—_Msg3is an offset from the preamble power.
  - 7. A method according to claim 6, further comprising, after sending the third message, using the processor to compute an updated transmit power for the shared uplink channel using fractional power control and sending from the transmitter a subsequent message on the uplink shared channel using the updated transmit power, wherein the updated transmit power P_PUSCH(i) is equal to:
    - P_PUSCH(i)=min{P_MAX,10 log₁₀(M_PUSCH(i))+P_O_—
      
      PUSCH(j)+α
      
      ·
      
      PL+Δ
      
      _TF(TF(i))+f(i)};
      
      wherein;
      
      P_O_—_PUSCH(i) is calculated from received signaling,α
      
      or an indication of α
      
      is received in signaling, andPL is path loss that is estimated from received signaling.
  - 8. The method according to claim 7, wherein α
    - =1 for the third message and for all retransmissions of the third message indicating full pathloss compensation, and α
      
      <
      
      1 for messages after the third message and all retransmissions of the third message indicating fractional pathloss compensation.
  - 9. The method according to claim 8, executed by a user equipment;
    - and wherein the third message comprises an indication of a power difference between the initial transmit power which is computed using full pathloss compensation and a fractional pathloss computation of the initial transmit power.

10. A computer readable memory storing a computer program that when executed by a processor results in actions comprising:
- initializing for i=0 a first power control adjustment state g(i) for an uplink control channel and a second accumulation power control adjustment state f(i) for an uplink shared channel to each reflect an open loop power control error;
  
  computing an initial transmit power for the uplink shared channel using full pathloss compensation, wherein the initial transmit power depends on a preamble power of a first message sent on an access channel, and is initialized with the second power control adjustment state f(0); and
  
  outputting the initial transmit power for transmission of a third message on the uplink shared channel.
- View Dependent Claims (11)
- - 11. The computer readable memory according to claim 10,wherein the second accumulation power control adjustment state f(i) for i=0 is initialized as:
    - P₀_—_UE_—_PUSCH+f(0)=Δ
      
      P_PC+Δ
      
      P_rampup;
      
      wherein;
      
      P₀_—_UE_—_PUSCHis a power control constant for the uplink shared channel that is specific for a user equipment which sends the first and third messages;
      
      Δ
      
      P_rampupis a ramp-up power for preamble transmissions; and
      
      Δ
      
      P_PCis a power control command indicated in a second message that is received in response to the first message.

12. An apparatus comprising:
- a processor configured to initialize for i=0 a first power control adjustment state g(i) for an uplink control channel and a second accumulation power control adjustment state f(i) for an uplink shared channel to each reflect an open loop power control error, and configured to compute an initial transmit power for the uplink shared channel using full pathloss compensation, wherein the initial transmit power depends on a preamble power of a first message sent on an access channel, and is initialized with the second power control adjustment state f(0); and
  
  a transmitter configured to send a third message on the uplink shared channel at the initial transmit power.
- View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
- - 13. The apparatus according to claim 12, wherein the first message comprises a random access request message, and:
    - the processor is configured to compute the preamble power using full pathloss compensation,the transmitter is configured to send on the access channel the first message;
      
      the apparatus comprises a receiver configured to receive, in response to the transmitter sending the first message, a second message that comprises an allocation of resources on which the third message is sent;
      
      the processor is configured, after the transmitter sends the third message, to compute an updated transmit power for the uplink shared channel using fractional power control;
      
      and the transmitter is configured to send a subsequent message on the uplink shared channel using the updated transmit power.
  - 14. The apparatus according to claim 12, wherein the second power control adjustment state f(i) for i=0 is initialized as:
    - P₀_—_UE_—_PUSCH+f(0)=Δ
      
      P_PC+Δ
      
      P_rampup;
      
      wherein;
      
      P₀_—_UE_—_PUSCHis a power control constant for the uplink shared channel that is specific for a user equipment;
      
      Δ
      
      P_rampupis a ramp-up power for preamble transmissions; and
      
      Δ
      
      P_PCis a power control command indicated in a second message received at a receiver of the apparatus in response to the transmitter sending the first message.
  - 15. The apparatus according to claim 12, wherein the first power control adjustment state g(i) for i=0 is initialized as:
    - P₀_—_UE_PUCCH+g(0)=Δ
      
      P_PC+Δ
      
      P_rampup;
      
      wherein;
      
      P_O_—_UE_—_PUCCHis a power control constant for the uplink control channel that is specific for a user equipment.
  - 16. The apparatus according to claim 15, wherein P_O_—
    - _UE_—_PUSCH=P_O_—_UE_—_PUCCH=0 when the processor computes initial values at i=0 of power control states for the respective shared and control channels.
  - 17. The apparatus according to claim 12,wherein the initial transmit power P_Msg3for i=0 is equal to:
    - P_Msg3=min{P_max,P_preamble+Δ
      
      _0,preamble_—_Msg3+Δ
      
      _PC_—_Msg3+10 log₁₀(M_PUSCH(i))+Δ
      
      _TF(TF(i))}in which;
      
      P_MAXis a maximum allowed transmission power;
      
      P_preambleis the preamble power of the first message;
      
      M_PUSCH(i) is determined from an uplink resource allocation of a second message received in response to sending the first message;
      
      Δ
      
      _TF(TF(i)) is calculated from received signaling;
      
      Δ
      
      _PC_—_Msg3is indicated by a power control command received at the receiver; and
      
      Δ
      
      _0,preamble_—_Msg3is an offset from the preamble power.
  - 18. The apparatus according to claim 17, wherein the processor is configured to compute an updated transmit power for the shared uplink channel using fractional power control and the transmitter is configured to send from the transmitter a subsequent message on the uplink shared channel using the updated transmit power, wherein the updated transmit power P_PUSCH(i) is equal to:
    - P_PUSCH(i)=min{P_MAX,10 log₁₀(M_PUSCH(i))+P_O_—_PUSCH(j)+α
      
      ·
      
      PL+Δ
      
      _TF(TF(i))+f(i)};
      
      wherein;
      
      P_O_—_PUSCH(j) calculated from received signaling,α
      
      or an indication of α
      
      is received in signaling, andPL is path loss that is estimated from received signaling.
  - 19. The apparatus according to claim 18, wherein α
    - =1 for the third message and for all retransmissions of the third message indicating full pathloss compensation, and α
      
      <
      
      1 for messages after the third message and all retransmissions of the third message indicating fractional pathloss compensation.
  - 20. The apparatus according to claim 18, in which the apparatus comprises a user equipment, and wherein the third message comprises an indication of a power difference between the initial transmit power which is computed using full pathloss compensation and a fractional pathloss computation of the initial transmit power.

Specification

Resources

Litigation Campaign Assessment

Current Assignee
Vivo Mobile Communication Co., Ltd. (Vivo Communication Technology Co. Ltd.)
Original Assignee
Nokia Solutions and Networks US LLC (Nokia Corporation)
Inventors
Korhonen, Juha S., Lindholm, Jari

Granted Patent

US 8,385,966 B2
Time in Patent Office

Days
Field of Search
US Class Current

455/522
CPC Class Codes

H04W 52/10   Open loop power control

H04W 52/146   Uplink power control

H04W 52/16   Deriving transmission power...

H04W 52/242   taking into account path loss

H04W 52/50   at the moment of starting c...

Method, apparatus and computer program for power control related to random access procedures

First Claim

4 Assignments

0 Petitions

Accused Products

Abstract

80 Citations

20 Claims

Specification

Solutions

Use Cases

Quick Links

Method, apparatus and computer program for power control related to random access procedures

First Claim

4 Assignments

Subscription Required

Subscription Required

0 Petitions

Subscription Required

Accused Products

Subscription Required

Abstract

80 Citations

20 Claims

Specification

Subscription Required

Solutions

Use Cases

Quick Links